For those members thinking about riding one way and flying the other (freighting the bike) also consider:-
Monday 7th March Public Holiday in WA, Labour Day
Riding west to Perth you will be travelling with the sun and get more daylight hours, in the afternoon you ride directly into the sun
Riding east from Perth you will be travelling in the opposite direction to the sun, less daylight hours, in the morning you ride directly into the sun. Maybe stating the obvious but it makes a difference. Some rows of electrical tape across the top of your visor act as a good sun visor.
There are some funny time zone changes across the Nullabor.
Would also suggest if you are riding via Coolgardie use the Goldfields Rd (Old Goldfields Highway) and The Great Southern Highway to travel between Tammin and The BP at The Lakes via York. Much nicer riding than the Great Western Highway and less traffic.